Dusty Solar Panels Affecting Efficiency and Performance on Rooftop Installation

Do Solar Panels Lose Efficiency Over Time?

Do you know how rapidly India’s solar power capacity is growing? According to a report, India generated 32 billion units of solar power in the 1st quarter of 2024.

Solar panels have become one of the most acceptable and practical methods of utilizing renewable energy sources in homes and businesses.

Large Array Of Dirty Solar Panels with Dust Accumulated on Them, Mounted on a Rooftop in an Urban Area

Cleaned Solar Panels After Using WattUp Cleaner, Mounted on a Rooftop, Surrounded by Trees and Buildings

However, potential customers have issues with its efficiency. It has been noticed that, over time, solar panels lose their efficiency.

The answer is yes. However, understanding the details of this process can help you make informed decisions about your solar energy system.

Thus, in this blog, we give you detailed information on solar panels and the reasons for their efficiency loss.

Understanding Solar Panel Degradation

Solar panel degradation is a slow process characterized by a gradual decline in the power generated by the panels.

The ability to convert sunlight into electricity slowly decreases over time.

This decay is influenced by the type of material used in their development, the environmental conditions, and the level of utilization.

What is the Rate of Efficiency Loss of Solar Panels?

The degradation rate of solar panels is measured in percent. According to research by the National Renewable Energy Laboratory (NREL), the average yearly degradation rate of solar panels is 0.5% to 1% per year.

This means that a solar panel that has been in use for 25 years may still be producing electricity at 75% to 87% efficiency.

  • For example, a 300-watt solar panel, after 25 years, will produce between 225 to 262. 5 watts.

While this is a reduction, it’s relatively modest and allows solar panels to remain functional and valuable over their typical lifespan of 25 to 30 years.

Factors Affecting Solar Panel Degradation

Several factors influence the rate at which solar panels lose efficiency:

Quality of Materials and Manufacturing:

It is controlled by the use of better materials and advanced technologies in the production process.

Materials used in solar panels can include polycrystalline silicon, thin-film materials like cadmium telluride (CdTe), and copper indium gallium selenide (CIGS).

However, monocrystalline silicon is considered the premium choice due to its superior performance.

High-end solar panels, generally made from monocrystalline silicon, typically come with better warranty protection and have lower degradation rates.

Environmental Conditions:

Solar panels are sensitive to weather conditions and may deteriorate due to fading, cracking, or peeling.

This occurs as they are exposed to heat, heavy snow, strong winds, heavy rain, and hail. Therefore, panels installed in comparatively warmer climate zones degrade at a slower pace.

Installation and Maintenance:

If not installed properly, solar panels may suffer physical damage or reduced energy collection efficiency.

Furthermore, without proper maintenance, dirt accumulation on the surfaces will negatively impact their efficiency.

Technology Improvements:

Technology has also extended the lifespan of solar panels. Innovations such as bifacial panels and improved anti-alkali coatings have made PV modules more efficient and durable in recent years.

What is the Mechanism Behind Degradation?

Understanding the mechanisms behind solar panel degradation helps to appreciate why and how they lose efficiency over time.

The primary degradation mechanisms include:

Photovoltaic (PV) Cell Degradation:

The PV cells, which are the active components of solar panels where light energy is converted into electricity, are affected by UV light and thermal cycling.

This exposure can cause cracking on the surface of the silicon cells, which is invisible to the naked eye but can impair their ability to generate electricity.

Encapsulation and Sealing Failures:

The solar panels are covered to protect them from the effects of weather and other environmental conditions that could impact their efficiency.

However, enclosing the panels can lead to the formation of moisture and oxidation, which are very detrimental to the cells.


This issue arises because some of the layers in the solar panel have delaminated, typically due to thermal stress or poor manufacturing.

Delamination creates regions where light cannot be collected, as there are gaps between the layers.


Solar panels have metallic parts where electrical connections are prone to corrosion, especially if the solar system is installed in an area of high humidity or near the sea.

This corrosion may interfere with the flow of electric current and, therefore, may impact the efficiency of the electrical equipment.

Steps for Mitigating Efficiency Loss

While some degradation is inevitable, some steps can be taken to mitigate efficiency loss and extend the lifespan of solar panels:

Choosing High-Quality Panels:

Investing in high-quality solar panels from reputable manufacturers can result in lower degradation rates and better long-term performance.

Regular Maintenance:

Cleaning the panels with a mild cleaning solution will ensure that there is no dirt on the surface of the panel.

Avoid using harsh chemicals and instead opt for WattUp, India’s first 100% non-acidic and biodegradable solar panel cleaning liquid.

It is essential to check for any signs of damage on the panel and ensure that the electrical connections are intact.

Optimal Installation:

Ensure that the right solar panels are chosen and mounted in a way that will minimize the thermal stress and physical impact on the panels.

Protective Measures:

Ensure that the panels have protected coats, such as anti-reflective coats and UV blockers.


By understanding and preventing the causes of efficiency loss, users can extend the service life and efficiency of their solar energy systems.

However, since the technology used in the production of solar panels is continually improving, there is a high probability that future models will be more durable and efficient.

Until then, keep your solar panels in good condition by using WattUp’s non-acidic, biodegradable solar panel cleaning solution.

If you need one for use, please contact us, and we will deliver it to your doorstep.

Shivam Bhamre